ASK THE INSPECTOR: Seepage may date back to foundation error

QUESTION: I would like your opinion on a situation with the basement in our home. We have a Logix Styrofoam/concrete basement in a six-year-old home. We had some water leakage into the basement a couple of years after the home was built. The water was nothing significant, but it was cause for some concern.

We had a contractor come in to assess the situation in the spring of 2011. He found some cracks in the foundation and suggested filling the cracks and sealing the basement where the water was coming in with crack injections with a compound that expands and seals once it comes into contact with water. After this was done, we did not have any water leakage in the basement for the rest of the spring or summer, even though it was the wettest in the past 50 years. Before, when we had the cracks in the foundation, if there was a heavy rain we would see some leakage.

In the spring of 2012, I noticed a small amount of water dribble in at the same location over a couple of days and then stop. We have not had any water problems since, even though this past spring has again been very wet.

We have had some heavy rains and I even soaked the area with a sprinkler on a couple of occasions and there was no leakage. My sump pump has been running since the spring and I do not think there is a problem with the weeping tile.

We are stumped as to where that little bit of water could have come from. We had considered excavating down to the footings to check the weeping tile, replace the blue skin and add dimple membrane to that part of the foundation. This would be very costly as well as messy, because we have a patio on that side of the house.

What could have been the source of this water? Do you have any possible suggestions or solutions? Is there a need to worry about any future leakage? We would appreciate your thoughts and opinions on this matter.

Sheldon Kaminski, Langenburg, Sask.

ANSWER: The answer to your question about the source of the moisture is easy, compared to the possible repair scenarios. It is difficult to figure out what is going on with your newer foundation without knowing the soil conditions or construction of the homes in your area. I will offer some suggestions, but will focus more on the likely true cause of your predicament.

Insulated concrete form (ICF) foundations are becoming very popular in some areas due to their excellent insulation properties and ease of installation. Unfortunately, with most newer building technologies there may be a learning curve for contractors who are used to older methods of construction.

More troubling than that is the possibility of amateurs assuming they have the expertise to use these new systems when they may be in over their heads. I would expect your home is a product of one of these two issues. If properly installed, there should be no reason for a new foundation to crack, especially an ICF foundation. This could be a problem with the concrete mix or installation, steel reinforcing, waterproofing, grading, or other defect.

Figuring out which factor or variables are deficient in your foundation may be tricky, and even if you dig down to the footing you may not be able to determine the issue unless you were present during the forming and pouring of the ICFs.

Regardless, there should be no reason for a foundation to have significant cracks in its first decade, unless a serious error was made. I am also surprised a contractor was so easily able to identify the cracks, as the polystyrene inside and outside of this system could hide them, unless they were large enough to displace the foam forms, exposing the concrete itself. If that is the situation, filling these with some form of expanding material will not be a permanent repair.

If the cracks are significant in size, they are due to movement of the foundation walls. This could occur due to early backfilling before the concrete was cured, insufficient reinforcement, or freezing concrete.

If any of these issues is the root cause of the moisture, there is no guarantee the foundation walls will not continue to move, even after injecting the cracks. Hydrostatic pressure from the soil outside the foundation is the likely source of the seepage and this may cause the cracks to expand further, or new ones to develop. If this occurs, it could allow the waterproofing membrane to become damaged, making future leakage a certainty.

Because of the serious implications of future foundation movement on your new home, immediate evaluation is critical. Inspection of the home by a professional structural engineer would be a good place to start. If you have the plans for the home, you may want to contact the engineer who reviewed the plans prior to construction to see if his or her specifications were followed. A stamp with the individual's name should be visible on the foundation plan. If this is not possible, a call to the local Association of Professional Engineers may provide assistance in locating an expert in your area.

Regardless of the specifics of where the water is coming from in your leaky new foundation, I'm afraid I suspect someone made a serious mistake during construction that has led to excessive cracking. Finding the defect should be the first priority, which will point the way to the proper repairs in preventing further deterioration and leakage.

Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and the president of the Canadian Association of Home & Property Inspectors -- Manitoba (www.cahpi.mb.ca). Questions can be emailed to the address below. Ari can be reached at (204) 291-5358 or check out his website at www.trainedeye.ca .

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